玉米醇溶蛋白/纳米TiO_2抗菌复合膜的制备及性质研究

以玉米醇溶蛋白(Zein)为成膜材料,添加甘油和纳米TiO_2制备抗菌复合膜。以断裂伸长率为考察指标,通过单因素和正交试验优化成膜工艺,并对其功能特性及结构进行表征。结果表明,Zein添加量15%、甘油添加量15%、干燥温度65 ℃为Zein/纳米TiO_2复合膜的最佳成膜工艺。FTIR和XRD分析表明,纳米TiO_2的添加使Zein/纳米TiO_2复合膜二级结构中的β-转角和β-折叠向α-螺旋和无规则卷曲结构转变,晶体结构整体趋于有序性排列。此外,抗菌试验和土壤降解试验表明,复合膜具有一定的抑菌性及土壤降解能力。     

玉米淀粉/卡拉胶/甘油复合膜的最佳成膜工艺研究

目的确定玉米淀粉/卡拉胶/甘油复合膜的最佳成膜工艺。方法以玉米淀粉为基材,与卡拉胶和甘油共混,通过流延法制备复合膜,以薄膜的机械性能为评价指标,通过单因素实验及正交实验来确定最佳成膜工艺。结果正交实验结果表明当玉米淀粉添加量为3%、卡拉胶添加量为30%、甘油添加量为25%时,玉米淀粉薄膜的机械性能最佳。结论本研究确定了玉米淀粉、卡拉胶和甘油的最佳成膜配比,为玉米淀粉膜的生产及应用提供理论基础。     

玉米秸秆纳米纤维素-淀粉膜的制备工艺优化及性能分析

本研究利用玉米秸秆纳米纤维素、玉米秸秆淀粉等作为成膜基材,通过共混流延法制备玉米秸秆纳米纤维素-淀粉膜。通过单因素实验和正交试验,对制备的纳米纤维素-淀粉膜的性能进行测定,考察各成膜基材对纳米纤维素-淀粉膜的机械性能、透湿系数、透光率、水溶性和透氧系数的影响,最终确定成膜液最佳配方组合:淀粉10.0%（W/V）、纳米纤维素5.0%（W/V）、羧甲基纤维素钠1.6%（W/V）、甘油2.3%（V/V）。在最优工艺条件下制备的纳米纤维素-淀粉膜综合效果最佳,并测得性能指标,膜厚（0.063±0.050）mm,抗拉强度14.92 MPa,断裂伸长率64.75%,透湿系数为2.19×10?12 g·m/m2·s·Pa,透光率87.60%,溶解时间97.00 s,透氧系数2.75×10?14 cm3·cm/cm2·s·Pa。     

超声波制备纳米SiO2-马铃薯淀粉复合膜性能优化及结构表征

为提高纳米SiO2在马铃薯淀粉膜中的分散性以增强纳米复合膜的包装保鲜性能,通过2?次超声波处理制备纳米SiO2-马铃薯淀粉复合膜,以马铃薯淀粉用量、甘油用量、纳米SiO2用量为考察因素,对纳米复合膜的性能进行正交试验优化,对其进行微观结构表征,以及对采后双孢蘑菇进行包装保鲜实验。结果表明,超声波使纳米SiO2较均匀地分散在马铃薯淀粉膜中,且适合超声波合成纳米复合膜的最佳膜液配比为马铃薯淀粉用量3.5?g/100?mL、甘油用量3?g/100?mL、纳米SiO2?用量0.3?g/100?mL。X-射线衍射光谱与傅里叶变换红外光谱分析证实超声波合成法使纳米SiO2与马铃薯淀粉分子间形成较强的氢键;紫外光谱分析表明超声波合成的纳米复合膜具有较好的抗紫外光作用。此外,超声波合成的纳米复合膜包装保鲜性能得到增强,其透水率、透氧率、水溶性较普通合成的纳米复合膜分别降低了30.22%、71.16%、39.61%,拉伸强度提高了17.82%,可较好地控制双孢蘑菇贮藏过程中活性氧的代谢,延长其货架期。     

纳米Ag/纳米TiO_2/CS复合膜材料的抗大肠杆菌特性研究

以壳聚糖CS为基质,添加纳米Ag和纳米TiO_2两种抗菌剂所制备的复合膜,针对大肠杆菌的抗菌性研究。实验根据前期单因素实验结果,设计了纳米Ag/纳米TiO_2/CS复合膜材料的三个因素的3个水平的正交实验,制备了不同优化工艺参数下的纳米Ag/纳米TiO_2/CS复合膜材料。同时,对制备的复合膜进行了抗菌性实验。探讨了优化工艺参数下的最优抗菌效果的工艺参数。结果表明:抗菌性最优工艺是:壳聚糖的浓度为4%,硫酸银的浓度为0.05mol/L,二氧化钛为0.007%时,纳米Ag/纳米TiO_2/CS复合膜材料的抑菌效果最好。研究结果为壳聚糖制备成生物质复合抗菌膜提供了理论及实验参考。     

玉米淀粉与小麦淀粉复合可食用膜工艺研究

以玉米淀粉和小麦淀粉为成膜基质,采用流延法制备可食用膜,以膜的力学性能作为考查指标,通过单因素实验研究质量比、山梨醇含量、柠檬酸含量、增强剂含量、糊化温度、糊化时间对力学性能的影响,在单因素基础上,以四因素三水平的正交实验优化的最佳制膜工艺条件。结果表明,在淀粉溶液浓度60 g/L,玉米淀粉和小麦淀粉质量比40∶60,山梨醇含量0.6%,柠檬酸含量2.5%,增强剂含量1.4%,糊化温度85℃,糊化时间40 min,干燥4~6 h的最佳制膜工艺条件下,复合膜的拉伸强度为14~15 MPa,断裂伸长率为30%~33%。     

滚筒干燥黑蒜粉工艺条件的研究

为优化滚筒干燥黑蒜粉的工艺条件,研究玉米淀粉添加量、滚筒温度和滚筒转速对成膜率的影响,在单因素实验的基础上,采用正交实验对干燥工艺条件进行优化,得到优化的工艺条件为淀粉添加量20%、转速4r/min、滚筒温度135℃。该条件下的成膜率达到95.8%。较热风干燥法和真空干燥法相比,该法时间短,质量好,表明滚筒干燥法是适宜的制备黑蒜粉的方法。     

玉米淀粉-聚乙烯醇复合薄膜生产工艺研究

以玉米淀粉和聚乙烯醇为基本成膜物质,添加适宜助剂,对其成膜特性进行了系统研究.通过单因素试验,研究了玉米淀粉质量浓度、聚乙烯醇质量浓度、增塑剂甘油体积分数和交联剂戊二醛体积分数对玉米淀粉-聚乙烯醇复合薄膜性能的影响,在单因素试验基础上进行了L9(34)正交试验,确定了玉米淀粉-聚乙烯醇复合薄膜最佳工艺参数.试验结果表明:在6.5 g/mL玉米淀粉和3.5 g/mL聚乙烯醇溶液中添加4.0%甘油和0.6%戊二醛,100℃水浴下交联反应25 min,刮膜后70～90℃恒温干燥45 min,所得到的可降解薄膜不仅呈现良好的外观,而且具有良好的抗张强度、伸长率和透光率,其抗张强度达27.18 MPa,伸长率达309.5%,透光率为51.97%.     

不同成膜温度对高粱秸秆粉/纳米ZnO/聚乙烯醇纳米复合膜理化性能和微观结构的影响

为提高农林废弃物的利用率及促进新型生物质材料的产业化生产,本文以高粱秸秆粉(Sorghum straw powder,SSP)、纳米ZnO、聚乙烯醇(Polyvinyl alcohol,PVA)等为主要成膜基材,采用共混流延法制备出高粱秸秆粉/纳米ZnO/聚乙烯醇(SSP/Nano-ZnO/PVA,SNP)纳米复合膜,研究SSP的加入及不同成膜温度(75、80、85、90、95℃)对SNP纳米复合膜厚度、抗拉强度(Tensile strength,TS)、阻隔性能、微观结构、光谱特性和热性能的影响。结果表明:SSP的加入能提高SNP纳米复合膜TS、阻隔性能及热性能;随着成膜温度的升高,SNP纳米复合膜TS和阻隔性能先变好后变差,当成膜为85℃时,SNP纳米复合膜性能最好(TS=31.22 MPa最大,水蒸气透过系数=1.32×10^-12 g/(cm·s·Pa)、水溶性=36.41%、溶胀度=238.41%最小),并通过SEM、AFM、FT-IR、TG分析表明该温度下SNP纳米复合膜表面光滑,截面致密,各基质间具有良好的相容性且热稳定性较好,综合性能优于其他成膜温度...     

改性玉米苞叶纤维素/纳米滑石粉/豌豆淀粉复合膜的制备及性能表征

为开发绿色可降解的食品包装材料,本文以豌豆淀粉（pea starch,PS）为主要成膜基质,改性玉米苞叶纤维素（modified corn bract cellulose,MCBC）、纳米滑石粉（nano talcum powder,NTP）为增强材料,甘油为增塑剂,共混流延制备复合膜,测定其膜性能,并用扫描电子显微镜、傅里叶红外光谱对复合膜进行表征,最后对其进行热重分析与降解性分析。结果表明,经单因素实验及正交试验得到最佳复合膜制备工艺为PS 8%,甘油2.5%,MCBC 0.8%,NTP 0.15%,在此条件下制得的复合膜厚度为0.042 mm,透光率32.58%,抗拉强度32.48 MPa,断裂伸长率33.61%,水蒸气透过率0.19×10?10 g/（m·s·Pa）,透油系数0.006 g·mm/m2d,吸水率55.79%,溶解度18.04%。扫描电子显微镜（scanning electron microscopy,SEM）结果显示,复合膜表面光滑均匀,结构致密;傅里叶红外光谱（Fourier transform infrared spectroscopy,FTIR）结果显示,MCBC、NTP、PS三者之间相容性良好,分子间氢键作用增强;热重分析（thermal gravimetric analyzer,TGA）结果显示,复合膜热分解温度为318.12 ℃,热稳定性提高;降解性分析表明土壤掩埋8 d时自然降解率为96.47%,可完全生物降解,本研究为MCBC/NTP/PS复合膜在食品工业中的应用提供了参考。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.